Process for the production of motor fuels



JMP 16, 1945- P. .1. HARRINGTON 2,367,348

POCESS FOR THE PRODUCTION OF MOTOR FUELS Filed OOb. 28, 1941 atented Jan. 16, 19/45 PROCESS FOR T PRODUCTION O FUELS l Paul-L Harring'ton, Mountainside, N. assignor to Standard Oil Development Company, a corporation of Delaware Application October 28, 1941, Serial No. 416,789

3 Claims.

The present invention relates to improved high quality motor fuels;l The invention more particularly relates-to the treatment of mineral oils boiling in the motor fuel boiling range with cata.- lyst of the character having the ability to desulfurize the same and is particularly concerned with a novel lmethod of producing motor fuels of high octane numbers and of high susceptibilities for knock improving agents by the use ofbauxite. l

This is a, continuation-impart of U. S. Serial No. 295,215 which was iiled September 16, d1939, and which issued as Patent No. 2,293,205 August 18, 1942.-

In accordance with the present process, suitable organic sulfur compounds are'added to petroleum oils boiling in the motor fuel range and the resulting 'mixture treated with bauxite or an equivalent desulfurizing catalyst under substantially noncracking conditions. A'A particularly preferred modification of the present invention is to add a suitable organic sulfur compound to petroleumfeed oils having a relatively low sulfur content which feed oils would not normally be desulfurized and to pass the reis introduced into clistilling unit I by means of oil feed line 2.' Temperature and pressure conditions are maintained to remove overhead fixed gases by means of line 3 and to segregate a prime cut fraction by means of line 4, a gas oil cut by means of line 5 and a reduced crude cut by means of line 6. It is to be understood that distilling unit I may comprise any suitable equip- .ment for segregating these fractions or equivalent fractions, as for. example, a series of crude stills, equivalent distillation towers or pipe stills. The gas oil and reduced crude are subjected to temperature and pressure conditions in cracking units 'I and 8 adapted to secure the formation of fractions boiling in the gasoline boiling range. These cracking units likewise may comprise any desirable modification. 'I'he cracked distillate which boils in the gasoline boiling range is introduced into debutanizer 9 bymeans of line I0.

Temperature and pressure conditions are maintainedv on debutanizer 9 in order to remove as bottoms a petroleum fraction boiling in the sulting mixture over bauxite. or an equivalent catalyst under substantially non-cracking conditions.

It is known in the art' to treat petroleum. oils having an undesirable naturally occurring high sulfur concentration with various desulfurizing catalyst, particularly with bauxite, in order to reduce the sulfur concentrated to the desired degree. However, heretofore it was assumed that no possible benefit could result by additional sulfur compounds being added to the petroleum oils prior to treating the same with bauxite or an equivalent desulfurizing catalyst. I have now discovered a process by which it is possible to produce motor fuels having unexpectedly high octane numbers and having high susceptibilities for knock-suppressing agents, as for example, tetraethyl lead and the like. In accordance with my process, a petroleum oil boiling in the motor fuel boiling range is mixed with a relatively small quantity of a suitable organic sulfur compound and the mixture passed. over bauxite or an equivalent desulfurizing catalyst under non-cracking conditions.

My invention may be readily understood by reference to the attached drawing illustrating one modification of the same.

For purposes of description the crude oil is taken to be a relatively low sulfur-crude, as for example, an East Texas crude. The crude oil range from yabout 200 to 420 F. The debutanizer bottoms are introduced into acid treating unit II by means of line I2 and then introduced into rerun still I4 by 'means of line I3. Temperature and pressure conditions are maintained in rerun still I4 so as to remove overhead a petroleum distillate oi"A the desired end point and to remove as a bottoms by means of line I5 the high boiling polymer fraction. The over head from debutanizer 9 is introduced into stabilizing unit I6 by means of line I'I and the fixed gases removed overhead from said stabilizing unit by means of line I8. The stabilizer bottoms are removed by means of line I9, caustic treated in treating unit 20, removed by means of line 2| and combined'with the overhead removed from unit I4 by means of line 22. The acid sludge from unit II isremoved by means of line 23 and treated in a manner to regenerate the acid. The caustic solution is introduced into treating unit 20 by means of line 24, withdrawn by means of line 25 and treated in unit 26 in a manner to regenerate the caustic. 4The petroleum fractions boiling inthe gasoline boiling range, which are segregated as stabilizer bottoms and overhead from the rerunning unit, are combined with the prime cut naphtha, removed by means of line 4 and mixed with a suitable organic sulfur` compound which is introduced by means of line 21. The mixture passes through heater 28 and mixer 29 and is introduced into bauxite treating unit 30. oil is removed from bauxite unit 30 by means o! The bauxite treated line 8| while other products are removed by means of line 32.

The process of the present invention may be widely varied, although it may be applied in the treatment of any petroleum oil boiling in but only by the following claims inwhich it is Although any organic sulfur compound may be utilized as an addition agent, the preferred method is to employ a sulfur compound corresponding to the type formula R-Sn-R' wherein R indicates an alkyl, S is sulfur, n is an integer from 1 to 2 and R' is a radical selected from the group composed or hydrogen and alkyl. The amount of the sulfur compound added will depend upon the particular mineral oil being treated, the sulfur content oi.' the oil, as well as I upon the. particular conditions employed in the bauxite treating unit. In general, when the low sulfur oils contain from .01 to .1% oi sulfur, it is preferred to add an organic sulfur compound containing a quantity of sulfur ranging from .05

to .5%. The preferred organic sulfur compounds are alkyl mercaptans and alkyl disuliides, particularly those alkyl mercaptans boiling in the range below the boiling range of butyl mercaptans. Under certain conditions it is very desirable to segregate mercaptans from onestage in the refining of the petroleum oil, as for example,

. in the soda regeneration step, and to vutilize these segregated mercaptans as addition agents for the petroleum oil being fed to the bauxite treating unit.

The conditions employed in the bauxite treating unit are non-cracking conditions and may vary widely. In general, it is preferred to desulfurize at a temperature in the range from about 400 F. to 850 F., preferably in the range above 800 F. Although atmospheric pressure may be employed, especially desirable results are secured when using pressures'in the range above y 100 lbs. per square inch, particularly in the range of about 350 to 450 lbs. per square inch. Although any catalyst having the ability to desulfurize the naphtha may be used, preferred results are obtained when utilizing bauxite, particularly when using bauxite in conjunction with low sulfur cracked naphtha. Although the process of the present invention will increase the susceptibility of the treated motor fuel with respect to any knock-suppressing agent, it is particularly eective in increasing the susceptibility of the motor fuel with respect to tetraethyl lead.

The process of the present invention is not to be limited by any theory or mode of operation desired to claim all novelty in so far as the prior fart permits.

I claim:

l. Process for the production of a motor fuel from a petroleum oil boiling in the range below about 420 F., having a high octane number and a high susceptibility for knock suppressing agents, said petroleum oil having a sulfur content of less than 0.1% and being of a character that it would not normally be desulfurized, comprising adding to said petroleum oil a sulfur compound corresponding to the type formula alkyl-Sn-R', wherein S issulfur, n is an integer of from 1 to 2 and R is a member selected from the group consisting of hydrogen and alkyl, the quantity of sulfur compound added to the petroleum oil being in the range to give from .05% to 0.5% of sulfur based on the oil, passing the oilover a catalyst comprising bauxite at a temperature in the range from about 400 F. to 850 F. and at a pressure in the range from about 100 to 450 pounds per square inch, controlling the temperature and pressure within said ranges in a manner that substantially no cracking of. the oil occurs.

2. Process for the production of a motor fuel from a petroleum oil boiling in the range below about 420 F., having a high octane number and a high susceptibility for knock suppressing agents, said petroleum oil having a sulfur content of less than 0.1% and ibeing of Aa character that it would not normally be desulfurized, comprising adding to said petroleum oil a mercaptan in an amount sufficient to give .05% to 0.5% of sulfur based on the oil, passing the oil over a catalyst comprising bauxite at a temperature in the range from about 400 F. to 850 F. and at a pressure in the range from about to 450 poundsper squareinch, controlling the temperature and pressure within said ranges in a manner that substantially no cracking of the oil occurs.

3. Process for the production of a motor fuel from a petroleum oil boiling in the range below about 420 F., having a high octane number and a high susceptibility for knock suppressing agents, said petroleum o'il having a sulfur content of less than 0.1% and being of a character that it would not normally be desulfurized, comprising adding to said petroleum oil an alkyl disulfide in an amount suilicient to give .05% to 0.5% of sulfur based on the oil, passing the oil over a catalyst comprising bauxite at a temperature in the range from about 400 F. to 850 F. and at a pressure in the range from about 100 to 450 pounds per square inch, controlling the temperature and pressure within said ranges in a manner that substantially no cracking of the oil occurs.

PAUL J'. HARRINGTON. 

